I was using Movable Type 3.34 which came out in January 2007 and was now badly outdated. The reason why I hadn’t upgraded is because I was using a lot of hacks and had made my own modifications to the core code.

A few months ago, I ran into major problems with spam comments. That got me thinking about an upgrade. I was, however, able to solve the spam issue with MT-Akismet.

I downloaded Movable Type 4.2, the latest version, and played around with it. I liked it, but I realized that none of the plugins I was using had an upgrade for MT4. Also, I could find very few amateur bloggers on Movable Type. Professional websites and blogs were mostly using Movable Type, but the rest of the bloggers had switched to WordPress long ago.

I had already been using WordPress for a private blog and so I decided to take a look at the latest version of WordPress and how I could migrate my blog to it.

There were a few things I had to give up: No more MathML or serving all pages as application/xhtml+xml; no OpenPGP signed comments.

I also had to modify the Movable Type export script and WordPress’s import script so I could keep the same post IDs and slugs (basenames) as well as import tags and convert the content based on the text filter used in Movable Type.